Formaldehyde

“ Prepare a calibration stock solution by dilution of 1 mL of 1 mg/mL formaldehyde stock solution to 100 mL with distilled water. Pipet aliquots of calibration stock solution (e.g., 40, 200, 750, 2000, 5000, and 10000 μL) into 10-mL volumetric flasks to prepare working standards. ”

“ Separating unmarked forms: Four-ply forms were used to examine the effects of separating unmarked forms on the emission of formaldehyde vapor. Thirty forms (120 sheets) were placed inside the chamber for each test. Sheets were separated at the rate of 1 form or 4 sheets/min. After the 30-min separating procedure, the sheets were left exposed in the chamber for the rest of the 1-hr sampling process. The sampling flow rate was approximately 0.5 L/min. The maximum average formaldehyde concentration for 3 replicates was 0.37 ppm after 1 hr. ”

“ FORMALIN, or Formaldehyde, CH2O or H·CHO, the first member of the series of saturated aliphatic aldehydes. It is most readily prepared by passing the vapour of methyl alcohol, mixed with air, over heated copper or platinum. In order to collect the formaldehyde, the vapour is condensed and absorbed, either in water or alcohol. It may also be obtained, although only in small quantities, by the distillation of calcium formate. At ordinary temperatures formaldehyde is a gas possessing a pungent smell ”

“ The A. M. A. Chemical Laboratory reported that Formitol Tablets contained formaldehyde (or para­form­aldehyde) , and ammonium compound, and some hexa­methylen­amin. It is probable that the formaldehyde (or para­form­aldehyde) was produced by the decomposition of hexa­methylen­amin originally present in the tablets but decomposed by long contact with the acid.128
These tablets differ from Hex-Iodin in that they really contain active formaldehyde and, therefore, possibly produce antiseptic effect in test-tube cultures. ”

“ Hence, if the half-neutralised Solution A1 (cf. p. 98) is diluted with water, taking equal volumes, and one-sixth of the volume of dilute formaldehyde (1:3) gradually added in the cold, condensation is not induced. When heated several hours an opalescent liquid results from which, however, no flocculent deposits separate when left for some time. Using a concentrated solution of formaldehyde (Experiment A2, p. 98) in the cold produces no reaction, but after heating for a time an opalescent liquid is obtained. Both liquids give only slight precipitates with gelatine. ”

“ The amount of water ordinarily mixed in formalin in the compounding of a formaldehyde fluid is not sufficient to satisfy the appetite of the formaldehyde for more water. When a formaldehyde fluid comes in contact with moisture laden skin, there will be a movement of moisture from the skin toward the formaldehyde fluid, thereby reducing the degree of moisture in the skin and in that way causing it to become dry. When the skin becomes dry, it changes in color the same as in natural evaporation. ”

“ Vb = volume of NaOH (mL) used for back-titration Vs = volume of formaldehyde stock solution (10.0 mL) ALTERNATE ANALYSIS PROCEDURE FOR THE DETERMINATION OF FORMALDEHYDE LIBERATED FROM DUST/FIBER SAMPLES Note: This analysis procedure should only be used where interferences to the chromotropic acid analysis are not present. These interferences include phenol, oxidizable organic material, other aldehydes and alcohols. For formaldehyde determination by the chromotropic acid method, a 4-mL aliquot of the solution resulting from the desorption and incubation of the filter (step 8.) ”

“ For particleboard— “ (aa) no higher than 0.05 parts per million of formaldehyde for 90 percent of 6 months of routine quality control testing data required under subparagraph (A) (ii) ; and “ (bb) no test result higher than 0.08 parts per million of formaldehyde. “ (IV) For thin medium-density fiberboard— “ (aa) no higher than 0.08 parts per million of formaldehyde for 90 percent of 6 months of routine quality control testing data required under subparagraph (A) (ii) ; and “ (bb) no test result higher than 0.11 parts per million of formaldehyde. ”

“ Sober's report I will begin at the root and look after some of the sprouts. That hybrid is the only one of my chinkapin group that has blighted at all.
In regard to the use of bichloride of mercury or formaldehyde, it seems to me that formaldehyde will be a better germicide than bichloride of mercury, because bichloride of mercury coagulates the albuminous part of the plasm and may destroy the cell structure, whereas the formaldehyde will be more penetrating and less injurious. One would need to know how strong a formaldehyde solution can be used safely. ”

“ The strength of solutions of formaldehyde may be ascertained by the addition of excess of standard ammonia to the aldehyde solution (hexamethylene tetramine being formed) , the excess of ammonia being then estimated by titration with standard acid. On the formation of formaldehyde by the oxidation of methane at high temperatures, see W.A. Bone (Journ. Chem. Soc., 1902, 81, p. 535; 1903, 83, p. 1074) . Formaldehyde also appears to be a reduction product of carbon dioxide (see Annual Reports of the Chemical Society) . ”

“ Erlenmeyer, even before the experimental work mentioned in the preceding paragraph had been reported, suggested that instead of assuming a separate breaking down of the carbon dioxide and water, it is easier to conceive that they are united in the cell-sap into carbonic acid and that this is reduced by the chlorophyll-containing protoplasm into formic acid and then to formaldehyde, as indicated by the following equations:
Like von Baeyer's hypothesis, this assumes that formaldehyde and oxygen are the first products of photosynthesis. ”

“ Volumetric flasks, 10-, 100-mL and 1 L. 8. Pipets, 0.1-, 0.5-, 1.0-, and 3-mL glass, delivery, with pipet bulb. 9. Graduated cylinders, glass, 25-mL. 10. Cotton gloves. 11. Equipment for standardizing formaldehyde stock solution, Burets, 50-mL. 12. pH meter. 13. Magnetic stirrer. 14. Beaker, 50-mL. 15. Vials, 5-mL. 16. Filters, 0.45 μm. 17. Scintillation vials, 20-mL.
SPECIAL PRECAUTIONS: Perchloric acid is a strong oxidizing agent, toxic by ingestion and inhalation and is a strong irritant. Use only in a hood. Formaldehyde is a suspect carcinogen [1,6] and should be handled in a hood. ”

“ The simplest carbohydrates known to occur commonly in plant tissues are the hexoses (see Chapter IV) having the formula C6H12O6, which is just six times that of formaldehyde, CH2O. Also, it is known that formaldehyde easily, and even spontaneously, polymerizes into more complex forms having the general formula (CH2O) n; trioxymethylene, C3H6O3, being a well-known example. Further, both trioxymethylene and formaldehyde itself can easily be condensed into hexoses, by simple treatment with lime water as a catalytic agent. ”

“ Then to 100 cubic centimeters of this solution of 250 grams of sodium sulphite (Na2SO3 + 7 H2O) in 750 grams water, add 5 cubic centimeters of the suspected formaldehyde solution. A strong red color is instantly produced. Titrate with normal sulphuric acid until the color disappears. As the exact disappearance of the color is not easily determined, a margin of from 0.1 to 0.2 cubic centimeters may be allowed without the exactness of the reaction being injured, since 1 cubic centimeter of normal acid answers to only 0.03 grams of formaldehyde. ”

“ For the purpose of condensing phenol with formaldehyde, it is not essential to first convert the phenol into the water-soluble phenolsulphonic acid, since it is possible to convert the condensation products of phenol and its derivatives, which are soluble in alkali, into water-soluble form by either heating the condensation products with concentrated solutions of formaldehyde and neutral sulphites, or by dissolving the condensation products in alkali and inducing reaction by means of formaldehyde bisulphite. ”

“ As formaldehyde readily undergoes aldol condensation into a syrupy fluid called formose, when a dilute aqueous solution of formaldehyde is saturated with calcium hydroxide and allowed to stand for several days, there was no difficulty in conceiving the transition from formaldehyde to the carbohydrates; for formose is a mixture containing several hexose sugars, and Fischer has succeeded in isolating therefrom acrose, a simple sugar having the same formula as glucose, namely: C6H12O6. ”

“ Place the tip of the syringe needle against the frit in the inlet of the sampler and eject the formaldehyde solution. e. Prepare the m edia working stand ard (steps 7.a and 7.b) . f. Prepare a dditional working standards (steps 8.b. through 8.e.) . g. Trans fer 3-m L aliquots of working standa rds to 4-m L vials, and analyze (steps 10, 12 an d 13) . h. Prepare calibration graph, peak area or height vs. μg formaldehyde per sample. 9. Fortify and analyze three quality control spikes and three analyst spikes to ensure that calibration graph is in control. ”

“ Supelco samplers were fortified with known quantities of free formaldehyde in water, and ca libration was performed with me dia standards prepared from Supelco samplers fortified with known quantities of free formaldehyde in water; average recoveries ranged from 96.3% to 99.3% for five levels at 1.00 to 20 :g of formaldehyde per sampler (pooled S r = 0.0316; n = 6 at each level) . In a storage study, six Supelco samplers were fortified with 4-μg quantities of free formaldehyde in water. ”

“ If the formaldehyde is not used up rapidly enough by the protoplasm, it kills the enzyme and the undecomposed hydrogen peroxide destroys the chlorophyll, which stops the whole photosynthetic process. Usher and Priestley were able to cause the photolysis of carbon dioxide and water into formaldehyde outside of a green plant, in the presence of a suitable catalyzing agent which continually destroys the hydrogen peroxide as fast as it is formed ”

“ The best results are obtained from the formaldehyde when the temperature of the room is 65° F. or over, with a relative humidity of at least 60%. While formaldehyde has the power [Pg 210] to kill spores it is not considered sufficient to disinfect in such dis-eases as anthrax and tetanus.
Formaldehyde gas kills all forms of microörganisms almost instantly but is not particularly destructive to higher form of life. It produces a marked irritation in the mucous membrane of the respiratory tract which may result in death to animals exposed to the gas for any length of time. ”

“ He demonstrated the possibility of "formaldehyde" being produced from carbonic acid and water, which is only possible, if—as is the case—oxygen is liberated. All plants in daylight exhale oxygen and absorb carbonic acid. Formaldehyde, a gaseous compound, is, as aldehydes in general are, very liable to condense to solid compounds by accumulating a greater number of atoms into one molecule. Baeyer expressed his belief that sugar, the composition of which agrees with that of formaldehyde multiplied by six, is the product of such a condensation. ”

“ Formalin, a watery solution of a gas known as formaldehyde, is a new disinfectant that recent experience has [Pg 81] demonstrated to be very useful. It may be used as a gas where rooms are to be disinfected, or applied as a liquid where desired. It is much more powerful in its action than sulfur, and it has a great advantage over mercury and other strong disinfectants, as it is not so poisonous to man as it is to the lower forms of life. ”

“ There is a chemical action set up between the methylene blue and the formaldehyde which will give to the tissues a greenish color which is quite objectionable. In this case you would inject some fluid which does not contain formaldehyde. A benzoate of soda or borax, or peroxide solution would do.
A good formula to use, when you know methylene blue has been used by the attending physician is:
For transportation, govern yourself according to the transportation rules. ”

“ Formaldehyde is a powerful germicide, but its penetrating vapor restricts its use. These disinfectants are but little used in the final sterilisation of apparatus, chiefly on account of the difficulty of effecting their complete removal, for the presence of even traces of these chemicals is sufficient to so inhibit or alter the growth of bacteria as to vitiate subsequent experiments conducted by the aid of apparatus sterilised in this manner. ”

“ Formaldehyde is viewed as a potential occupational carcinogen SAMPLING: [4,5] . 1.
2. 3.
4.
Calibrate each personal sampling pump with a representative sampler in line. Break ends of the sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 0.01 and 0.10 L/min for a total sample size of 1 to 36 L. NOTE: Formaldehyde reacts with 2- (hydroxymethyl) piperidine on the sorbent bed during sampling. Sampling rate is limited by the speed of this reaction. ”

“ It is hardly necessary to remind physicians that the use of tablets containing hexa­methylen­amin or other formaldehyde compounds can neither cure respiratory infections, nor even confer protection against such infections. To be effective, formaldehyde would need to be supplied to the entire respiratory tract continuously for some time or else in concentrations that would be distinctly irritant and damaging to the tissues. Saliva-dissolved tablets, obviously cannot reach the nasal or tracheal mucosae directly ”